Your guide to the Solar System and the night sky
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🌎  Observing from: Greenwich, United Kingdom [change]
🌅 Sunrise: 6:41  ☀️ Transit: 13:03  🌅 Sunset: 19:26

21 Monocerotis

21 Monocerotis is a variable main-sequence star in the constellation of Monoceros.

21 Monocerotis visual magnitude is 5.45. Because of its reltive faintness, 21 Monocerotis should be visible only from locations with dark skyes, while it is not visible at all from skyes affected by light pollution.

The table below summarizes the key facts about 21 Monocerotis:

21 Monocerotis is above the horizon from Greenwich, United Kingdom [change]. Altitude: 14°.

Celestial coordinates and finder chart of 21 Monocerotis

21 Monocerotis is situated close to the celestial equator, as such, it is at least partly visible from both hemispheres in certain times of the year. Celestial coordinates for the J2000 equinox as well as galactic coordinates of 21 Monocerotis are provided in the following table:

07h 11m 23s
-00° 18’ 06”

The simplified sky map below shows the position of 21 Monocerotis in the sky:

Finder chart 21 Monocerotis star
Simplified finder chart for 21 Monocerotis.

Visibility of 21 Monocerotis from your location

Location: Greenwich, United Kingdom [change]
Latitude: 51° 28’ 47” N
Longitude: 0° 00’ 00” E
Timezone: Europe/London

Today's 21 Monocerotis rise, transit and set times from Greenwich, United Kingdom [change] are the following (all times relative to the local timezone Europe/London):

Azimuth: 90.3°
Max altitude: 38.2°
Azimuth: 269.7°
21 Monocerotis is above the horizon from Greenwich, United Kingdom

Digitized Sky Survey image of 21 Monocerotis

The image below is a photograph of 21 Monocerotis from the Digitized Sky Survey 2 (DSS2 - see the credits section) taken in the red channel. The area of sky represented in the image is 0.5x0.5 degrees (30x30 arcmins). The proper motion of 21 Monocerotis is -0.031 arcsec per year in Right Ascension and -0.011 arcsec per year in Declination and the associated displacement for the next 10000 years is represented with the red arrow.

Image of 21 Monocerotis star
DSS2 image of 21 Monocerotis. The red arrow shows the motion of 21 Monocerotis during the next 10000 years (-5.17 arcmin in Right Ascension and -1.83 arcmin in declination);

Distance of 21 Monocerotis from the Sun and relative movement

21 Monocerotis is distant 261.01 light years from the Sun and it is moving far from the Sun at the speed of 30 kilometers per second.

80.06 pc
261.01 ly
30 km/s
-0.031 arcsec/year
-0.011 arcsec/year

Spectral properties of 21 Monocerotis

21 Monocerotis belongs to spectral class A8 and has a luminosity class of V corresponding to a main-sequence star.


The red dot in the diagram below shows where 21 Monocerotis is situated in the Hertzsprung–Russell diagram.

HR Diagram
H-R diagram showing the position of 21 Monocerotis. Attribution: Richard Powell / CC BY-SA

Alternative designations of 21 Monocerotis

21 Monocerotis